A comparative effectiveness pilot study of teriparatide for medication-related osteonecrosis of the jaw: daily versus weekly administration

Treatment period and changes in bone markers according to the application of teriparatide in treating medication-related osteonecrosis of the jaw

BACKGROUND

This study aimed to explore the effects of teriparatide (TPTD) on treatment duration, surgical procedures, and bone turnover markers in medication-related osteonecrosis of the jaw (MRONJ).

METHODS

We analyzed 76 patients with MRONJ post-treatment and divided them into conservative/surgical and TPTD/non-TPTD groups. Key assessments included treatment duration, surgery count, and changes in bone markers (serum C-terminal telopeptide of type 1 collagen [CTX], osteocalcin [OC], procollagen type 1 N-terminal propeptide [P1NP], parathyroid hormone [PTH], 25-OH-vitamin D [25(OH)D], calcium, and inorganic phosphorus) measured at the initial and post-treatment stages.

RESULTS

TPTD-treated surgical patients experienced shorter treatment periods and underwent fewer surgeries than did non-TPTD counterparts. Post-treatment, both groups showed significant increases in CTX, OC, and 25(OH)D levels. P1NP elevation was significant only in the non-TPTD group. Although the PTH levels decreased in both groups, the difference was not statistically significant. Calcium and phosphorus levels increased in both groups, but only calcium levels increased significantly in the TPTD group. Additionally, TPTD-treated patients showed significant improvements in T-scores, particularly in the lumbar spine and femur neck, compared to the non-TPTD group.

CONCLUSIONS

TPTD administration during MRONJ treatment potentially reduces the need for surgical intervention and accelerates recovery, significantly affecting bone metabolism. These findings highlight TPTD's role in enhancing the efficacy of MRONJ treatment. TPTD could potentially offer the dual benefit of promoting bone healing and reducing the need for surgical intervention, thus improving overall outcomes for patients with MRONJ.

Medication-related osteonecrosis of the jaw: evolving research for multimodality medical management

PURPOSE

Medication-related osteonecrosis of the jaw (MRONJ) is a debilitating side effect of antiresorptive and antiangiogenic agents that can lead to progressive bone destruction in the maxillofacial region. Dental surgery, including tooth extractions, commonly trigger the onset of MRONJ. While guidelines suggest avoiding extraction when possible, complete avoidance is not always feasible, as necrosis can develop from dental and periodontal disease without dental procedures. The goal of this article is to provide an update review of current preventive and therapeutic approaches for MRONJ.

METHODS

A comprehensive electronic search was conducted on PubMed/MEDLINE, Embase, and Scopus databases. All English articles encompassing randomized controlled trials, systematic reviews, observational studies, and case studies were reviewed. The current medical treatments and adjuvant therapies for managing MRONJ patients were critically assessed and summarized.

RESULTS

Pentoxifylline and alpha tocopherol (PENT-E), teriparatide, photobiomodulation (PBM), photodynamic therapy (PDT), and the use of growth factors have shown to enhance healing in MRONJ patients. Implementing these methods alone or in conjunction with surgical treatment has been linked to reduced discomfort and improved wound healing and increased new bone formation.

DISCUSSION

While several adjuvant treatment modalities exhibit promising results in facilitating the healing process, current clinical practice guidelines predominantly recommend antibiotic therapy as a non-surgical approach, primarily addressing secondary infections in necrotic areas. However, this mainly addresses the potential infectious complication of MRONJ. Medical approaches including PENT-E, teriparatide, PBM, and PDT can result in successful management and should be considered prior to taking a surgical approach. Combined medical management for both preventing and managing MRONJ holds potential for achieving optimal clinical outcomes and avoiding surgical intervention, requiring further validation through larger studies and controlled trials.

Dynamic morphometric changes in the mandibular osteocytic lacunae of ovariectomized rats in response to teriparatide, as revealed by three-dimensional fluorescence analyses: Possible involvement of osteocytic perilacunar remodeling

OBJECTIVES

Teriparatide [TPTD; human parathyroid hormone (hPTH1-34)] is an anti-osteoporotic drug with bone anabolic effects. Clinical and preclinical studies have indicated that TPTD has value in oral and maxillofacial bone therapies, including jawbone regeneration, periodontal tissue repair, and the treatment of medication-related osteonecrosis of the jaw. However, it is unclear whether the craniofacial bones respond to TPTD similarly to the axial and appendicular bones. Recent studies showed that TPTD acts on both osteocytes and osteoblasts. This study aimed to characterize distinct craniofacial bone sites, with a focus on morphometric changes in osteocytic lacunae in ovariectomized rats receiving TPTD.

METHODS

Conventional bone histomorphometric analyses of mandibular and parietal bone sections were conducted. High-resolution confocal imaging-based three-dimensional fluorescence morphometric analyses of osteocytic lacunae in distinct mandibular and parietal bone sites were conducted.

RESULTS

We observed dynamic changes in the morphometric characteristics of osteocytic lacunae specifically in alveolar and other mandibular bone sites upon TPTD administration.

CONCLUSIONS

These findings suggest that osteocytes in mandibular bone (specifically, alveolar bone) have unique functional characteristics of osteocytic perilacunar remodeling.

Reliability of early stage symptoms/clinical findings of osteonecrosis of the jaw: Japanese Osteoporosis Intervention Trial-05 (JOINT-05)

INTRODUCTION

To investigate the differences in the incidence rates of suspected stage 0/1 osteonecrosis of the jaw (ONJ) and incidence risk of relevant clinical findings of suspected stage 0 ONJ between patients treated with sequential therapy comprising weekly teriparatide for 72 weeks followed by alendronate for 48 weeks vs. those who received monotherapy with alendronate for 120 weeks.

MATERIALS AND METHODS

Suspected stage 0/1 ONJ was defined by non-specific symptoms. Tooth mobility and periodontal symptoms (gingival bleeding, swelling, and/or pain) were selected as clinical findings of suspected stage 0 ONJ. Poisson regression models were applied to calculate the incidence rate ratios of suspected stage 0/1 between the teriparatide group (TG) and alendronate group (AG). Generalized linear models were used to calculate the risk ratios of clinical findings between groups.

RESULTS

Two hundred and sixty-one participants in the TG and 344 in the AG answered a structured questionnaire on oral health and were included in this study. There were no significant differences between the groups in the incidence rate of suspected stage 0/1 ONJ at both 72 and 120 weeks. The risk ratio of the TG to AG for tooth mobility was 0.34 (95% confidence interval [CI] 0.13-0.88, p = 0.02) at 72 weeks and 0.90 (95% CI 0.40-2.03, p = 0.83) at 120 weeks. The incidence rate of tooth mobility related to periodontal symptoms decreased in the TG and increased in the AG during the study.

CONCLUSION

Tooth mobility accompanied by clinical periodontal symptoms may be a useful early sign of stage 0 ONJ.

Comparison of the Effectiveness of Conservative and Surgical Treatment of Medication-Related Osteonecrosis of the Jaw: a Systematic Review

Objectives

The objective of this systematic review is to evaluate the current knowledge on the effectiveness of conservative and surgical treatment of medication-related osteonecrosis of the jaw.

Material and Methods

MEDLINE (PubMed), ScienceDirect and Cochrane Library search in combination with hand-search of relevant journals was conducted including human studies published in English between January 2017 and February 2023. Studies assessing treatment strategies for medication-related osteonecrosis of the jaw (MRONJ) were included. Quality and risk-of-bias assessment were evaluated by Joanna Briggs Institute (JBI) Risk of Bias tool.

Results

A total of 4227 articles were screened from which 9 studies (7 cohort studies and 2 randomized controlled trials) met the inclusion criteria and were included in the final data synthesis. Two studies evaluate effectiveness of conservative approaches for treating MRONJ, 5 studies evaluate surgical approaches effectiveness, and 2 studies compare between those approaches. The follow-up period ranged from 6 months to 60 months. According to bias assessment, the mean JDI score of the included studies was > 9 ("low risk of bias"). The stage of the disease, the procedure performed on the patient and the results of the treatment were presented.

Conclusions

Surgical therapy seems to be superior to conservative therapy for the management of adverse stages medication-related osteonecrosis of the jaws, while conservative treatment appears to yield good outcomes at asymptomatic patients with early stages of the disease.

Medication-Related Osteonecrosis of the Jaws: A Comparison of SICMF-SIPMO and AAOMS Guidelines

(1) Background: Medication-related osteonecrosis of the jaws (MRONJ) is an adverse drug reaction characterized by progressive bone disruption and necrosis in the mandibular and/or maxillary bones. It occurs in individuals who have received antiresorptive drugs without prior radiotherapy. Since its first reported cases in the USA in 2003, extensive literature has emerged worldwide, leading to significant advancements in understanding MRONJ's pathogenesis and management. (2) Results: This article aims to compare the current national recommendations provided by the Italian Society of Maxillofacial Surgery (SICMF)/Italian Society of Oral Pathology and Medicine (SIPMO) and the American Association of Oral and Maxillofacial Surgeons (AAOMS). (3) Conclusions: Historically, the AAOMS advocated for a more conservative approach compared to the Italian guidelines. However, in their 2022 update, the AAOMS adopted a different perspective based on reported evidence, highlighting the advantages of early surgical treatment. Despite resolving some initial controversies, differences still exist between the two sets of recommendations, particularly regarding diagnosis and staging.

Interventions for managing medication-related osteonecrosis of the jaw

BACKGROUND

Medication-related osteonecrosis of the jaw (MRONJ) is a severe adverse reaction experienced by some individuals to certain medicines commonly used in the treatment of cancer and osteoporosis (e.g. bisphosphonates, denosumab, and antiangiogenic agents), and involves the progressive destruction of bone in the mandible or maxilla. Depending on the drug, its dosage, and the duration of exposure, this adverse drug reaction may occur rarely (e.g. following the oral administration of bisphosphonate or denosumab treatments for osteoporosis, or antiangiogenic agent-targeted cancer treatment), or commonly (e.g. following intravenous bisphosphonate for cancer treatment). MRONJ is associated with significant morbidity, adversely affects quality of life (QoL), and is challenging to treat. This is an update of our review first published in 2017.

OBJECTIVES

To assess the effects of interventions versus no treatment, placebo, or an active control for the prophylaxis of MRONJ in people exposed to antiresorptive or antiangiogenic drugs. To assess the effects of non-surgical or surgical interventions (either singly or in combination) versus no treatment, placebo, or an active control for the treatment of people with manifest MRONJ.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched four bibliographic databases up to 16 June 2021 and used additional search methods to identify published, unpublished, and ongoing studies.  SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing one modality of intervention with another for the prevention or treatment of MRONJ. For 'prophylaxis of MRONJ', the primary outcome of interest was the incidence of MRONJ; secondary outcomes were QoL, time-to-event, and rate of complications and side effects of the intervention. For 'treatment of established MRONJ', the primary outcome of interest was healing of MRONJ; secondary outcomes were QoL, recurrence, and rate of complications and side effects of the intervention.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results, extracted the data, and assessed the risk of bias in the included studies. For dichotomous outcomes, we reported the risk ratio (RR) (or rate ratio) and 95% confidence intervals (CIs).

MAIN RESULTS

We included 13 RCTs (1668 participants) in this updated review, of which eight were new additions. The studies were clinically diverse and examined very different interventions, so meta-analyses could not be performed. We have low or very low certainty about available evidence on interventions for the prophylaxis or treatment of MRONJ. Prophylaxis of MRONJ Five RCTs examined different interventions to prevent the occurrence of MRONJ. One RCT compared standard care with regular dental examinations at three-month intervals and preventive treatments (including antibiotics before dental extractions and the use of techniques for wound closure that avoid exposure and contamination of bone) in men with metastatic prostate cancer treated with zoledronic acid. The intervention seemed to lower the risk of MRONJ (RR 0.10, 95% CI 0.02 to 0.39, 253 participants). Secondary outcomes were not evaluated. Dentoalveolar surgery is considered a common predisposing event for developing MRONJ and five RCTs tested various preventive measures to reduce the risk of postoperative MRONJ. The studies evaluated plasma rich in growth factors inserted into the postextraction alveolus in addition to standardised medical and surgical care versus standardised medical and surgical care alone (RR 0.08, 95% CI 0.00 to 1.51, 176 participants); delicate surgery and closure by primary intention versus non-traumatic tooth avulsion and closure by secondary intention (no case of postoperative MRONJ in either group); primary closure of the extraction socket with a mucoperiosteal flap versus application of platelet-rich fibrin without primary wound closure (no case of postoperative MRONJ in either group); and subperiosteal wound closure versus epiperiosteal wound closure (RR 0.09, 95% CI 0.00 to 1.56, 132 participants).  Treatment of MRONJ Eight RCTs examined different interventions for the treatment of established MRONJ; that is, the effect on MRONJ cure rates.  One RCT analysed hyperbaric oxygen (HBO) treatment used in addition to standard care (antiseptic rinses, antibiotics, and surgery) compared with standard care alone (at last follow-up: RR 1.56, 95% CI 0.77 to 3.18, 46 participants).  Healing rates from MRONJ were not significantly different between autofluorescence-guided bone surgery and conventional bone surgery (RR 1.08, 95% CI 0.85 to 1.37, 30 participants). Another RCT that compared autofluorescence- with tetracycline fluorescence-guided sequestrectomy for the surgical treatment of MRONJ found no significant difference (at one-year follow-up: RR 1.05, 95% CI 0.86 to 1.30, 34 participants).  Three RCTs investigated the effect of growth factors and autologous platelet concentrates on healing rates of MRONJ: platelet-rich fibrin after bone surgery versus surgery alone (RR 1.05, 95% CI 0.90 to 1.22, 47 participants), bone morphogenetic protein-2 together with platelet-rich fibrin versus platelet-rich fibrin alone (RR 1.10, 95% CI 0.94 to 1.29, 55 participants), and concentrated growth factor and primary wound closure versus primary wound closure only (RR 1.38, 95% CI 0.81 to 2.34, 28 participants).   Two RCTs focused on pharmacological treatment with teriparatide: teriparatide 20 μg daily versus placebo in addition to standard care (RR 0.96, 95% CI 0.31 to 2.95, 33 participants) and teriparatide 56.5 μg weekly versus teriparatide 20 μg daily in addition to standard care (RR 1.60, 95% CI 0.25 to 1.44, 12 participants).

AUTHORS CONCLUSIONS

Prophylaxis of medication-related osteonecrosis of the jaw One open-label RCT provided some evidence that dental examinations at three-month intervals and preventive treatments may be more effective than standard care for reducing the incidence of medication-related osteonecrosis of the jaw (MRONJ) in individuals taking intravenous bisphosphonates for advanced cancer. We assessed the certainty of the evidence to be very low. There is insufficient evidence to either claim or refute a benefit of the interventions tested for prophylaxis of MRONJ in patients with antiresorptive therapy undergoing dentoalveolar surgery. Although some interventions suggested a potential large effect, the studies were underpowered to show statistical significance, and replication of the results in larger studies is pending. Treatment of medication-related osteonecrosis of the jaw The available evidence is insufficient to either claim or refute a benefit, in addition to standard care, of any of the interventions studied for the treatment of MRONJ.

Current Trends in Adjuvant Therapies for Medication-Related Osteonecrosis of the Jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a refractory disease, and a standard protocol for its treatment has not yet been established. In addition, owing to the old age of MRONJ patients and various complications, treatment goals focus on relieving the symptoms and improving the quality of life. For this reason, different treatments such as conservative, surgical, and adjunctive treatments have been attempted. In particular, adjunctive treatment, which is effective for promoting healing and reducing recurrence, is gaining increasing interest, and several studies and clinical trials related to it have been published. Representative adjuvant therapies include teriparatide, recombinant human bone morphogenetic protein-2, hyperbaric oxygen, photobiomodulation and platelet concentrates. All have generally shown beneficial effects; however, no standard protocol for adjunctive treatment exists. Therefore, in this literature review, we briefly summarized the different adjuvant therapies and reviewed clinical reports to help decide whether to use adjuvant therapies in treating patients with MRONJ.

Is teriparatide therapy effective for medication-related osteonecrosis of the jaw? A systematic review and meta-analysis

Considering the lack of studies determining the real TPTD efficacy in individuals who develop MRONJ, our objective was to combine the available data on MRONJ cases treated with TPTD. The findings demonstrated that TPTD in combination with another therapy, especially antibiotic therapy, can be considered an effective protocol for MRONJ.

PURPOSE

To integrate the data published on the effect of teriparatide (TPTD) therapy on cases of medication-related osteonecrosis of the jaws (MRONJ) into a comprehensive analysis of clinical features.

METHODS

An electronic search was undertaken in six databases. Descriptive analyses of clinicodemographic data of MRONJ were carried out. Poisson regression was also run to evaluate predictors of total resolution of MRONJ treated with TPTD.

RESULTS

Twenty-six publications comprising 111 cases were included. Most reported cases affected female individuals (82.0%) with a mean age of 76.54 years. Osteoporosis (76.5%) represented the main reason for using antiresorptive drugs, with bisphosphonates (98.1%) as the most frequently reported. Comorbidities were commonly present. The most related trigger factor of MRONJ was dental extraction (61.7%). Mandible (75.8%) was the most commonly affected site, with a mean evolution time of 5 months. MRONJ stage 2 (61.3%) was the most prevalent. Regarding TPTD treatment, in 45.1% cases, TPTD was used alone, with the total resolution being observed in 59.5% of the individuals. Associated therapy (54.9%) included surgery, antibiotic therapy, and laser therapy. Mean follow-up was 8.7 months. Poisson regression demonstrated that individuals with MRONJ stage 1 were 1.21 times more likely to present total resolution of osteonecrosis than individuals with MRONJ stage 3 (CI = 1.02-1.43; p < 0.023). Individuals who had undergone treatment with TPTD in association with another therapeutic modality were 1.21 times more likely to present total resolution of osteonecrosis than those who had undergone treatment with TPTD alone (CI = 1.40-1.39; p < 0.010).

CONCLUSION

TPTD in combination with another therapy, especially antibiotic therapy, should be considered an effective therapeutic modality for MRONJ.

Parathyroid Hormone 1 Receptor Signaling in Dental Mesenchymal Stem Cells: Basic and Clinical Implications

Parathyroid hormone (PTH) and parathyroid hormone-related protein (PTHrP) are two peptides that regulate mineral ion homeostasis, skeletal development, and bone turnover by activating parathyroid hormone 1 receptor (PTH1R). PTH1R signaling is of profound clinical interest for its potential to stimulate bone formation and regeneration. Recent pre-clinical animal studies and clinical trials have investigated the effects of PTH and PTHrP analogs in the orofacial region. Dental mesenchymal stem cells (MSCs) are targets of PTH1R signaling and have long been known as major factors in tissue repair and regeneration. Previous studies have begun to reveal important roles for PTH1R signaling in modulating the proliferation and differentiation of MSCs in the orofacial region. A better understanding of the molecular networks and underlying mechanisms for modulating MSCs in dental diseases will pave the way for the therapeutic applications of PTH and PTHrP in the future. Here we review recent studies involving dental MSCs, focusing on relationships with PTH1R. We also summarize recent basic and clinical observations of PTH and PTHrP treatment to help understand their use in MSCs-based dental and bone regeneration.

Review of Myeloma Therapies and Their Potential for Oral and Maxillofacial Side Effects

Simple Summary

Myeloma is a common cancer involving the bone marrow. Some of the medications used in the treatment of myeloma, including those that reduce the risk of bone fractures, can increase the chance of side effects occurring in the jawbone. The most serious complication in the jawbone is called medication-related osteonecrosis, meaning part of the jawbone dies. The aim of this review is to highlight some of the medications that are implicated and other risk factors that can contribute to osteonecrosis. Suggestions to prevent this complication from occurring are described. Conventional methods of treating established medication-related osteonecrosis of the jawbone are outlined as well as emerging new treatments.

Abstract

Myeloma is a common haematological malignancy in which adverse skeletal related events are frequently seen. Over recent years, treatment for myeloma has evolved leading to improved survival. Antiresorptive therapy is an important adjunct therapy to reduce the risk of bone fractures and to improve the quality of life for myeloma patients; however, this has the potential for unwanted side effects in the oral cavity and maxillofacial region. Osteonecrosis of the jaw related to antiresorptive medications and other myeloma therapies is not uncommon. This review serves to highlight the risk of osteonecrosis of the jaw for myeloma patients, with some suggestions for prevention and management.

Recurrence-Related Factors of Medication-Related Osteonecrosis of the Jaw: A Five-Year Experience

PURPOSE

The treatment of medication-related osteonecrosis of the jaw (MRONJ) is greatly challenging for surgeons. In this study, we reviewed patients with MRONJ treated in our hospital in the past 5 years and explored the risk factors of recurrence.

METHODS

A retrospective cohort study was conducted to review the patients with MRONJ from January 1, 2016 to December 31, 2020. All patients received a monthly intravenous application of zoledronic acid. The primary outcome variable was the treatment outcome during follow-up. The predictor variables were local and systemic factors related to the treatment outcome. Multivariate logistic regression analysis was performed to identify the risk factors of recurrence after MRONJ treatment.

RESULTS

A total of 58 patients (62 sites) were included in this study. In multivariate regression analysis, the risk factor associated with recurrence after MRONJ treatment was the duration of medication of more than 18 months (odds ratio = 7.346; 95% confidence interval: 1.461-36.946; P = .016).

CONCLUSIONS

Using zoledronic acid over 18 months may increase the risk of recurrence in MRONJ patients.

Effects of pre-extraction intermittent PTH administration on extraction socket healing in bisphosphonate administered ovariectomized rats

The purpose of this study was to investigate the effect of administering intermittent parathyroid hormone (iPTH) before tooth extraction versus after tooth extraction on the risk of developing MRONJ in experimental animal model. Twenty-five ovariectomized rats received 6 weeks of bisphosphonate therapy. They were classified into 3 groups, based on the timing of the medication, as Control, Pre-PTH and Post-PTH groups. For Control group, normal saline was administered before and after tooth extraction. iPTH was administered during 4 weeks before tooth extraction for Pre-PTH group and after tooth extraction for Post-PTH group. The animals were euthanized 8 weeks after tooth extraction. Macroscopic, histological, micro-computed tomography (micro-CT), and histomorphometric examinations were conducted. The incidences of impaired healing were 11.11% both in Pre-PTH and Post-PTH groups, which was lower than the Control group (42.86%). Bone healing in the extraction socket, based on micro-CT and histomorphometry evaluations, was best in Post-PTH and worst in Control group. The Pre-PTH group showed moderate healing pattern. Despite of limitations in this study, the authors identified Pre-PTH group seems to have positive effect on extraction socket healing. With regard to timing, administering iPTH after tooth extraction was superior to applying it before tooth extraction.

Successful Non-surgical Management of a Mandible Fracture Secondary to Medication-related Osteonecrosis of the Jaw: A Unique Case Report

Background:

Medication-related osteonecrosis of the jaw (MRONJ) may be a severe side effect of bone-modifying agents.

Objective:

Pathologic fractures treatment in patients with MRONJ remains challenging. The authors reported a unique case of successful non-surgical management of a mandible fracture secondary to MRONJ.

Methods:

A 78-year-old osteoporotic woman with a 4-year history of oral bisphosphonate therapy and a compromised dental condition developed an MRONJ-related right mandibular body fracture. Treatment consisted of systemic antibiotic administration (amoxiclav and metronidazole) and chlorhexidine mouthwash.

Results:

Follow-up visits revealed progressive healing of the mandibular fracture with bone callus formation and complete recovery of the ipsilateral lip and chin sensitivity after one year.

Conclusion:

Non-surgical management of pathological fractures related to MRONJ might be of interest in patients that refuse any type of surgery, but preventive measures, such as careful dental examination, should be taken before start antiresorptive therapy and during the treatment. The authors reported the first case in the literature of successful management of a mandibular fracture secondary to MRONJ with only antibiotics and mouthwashes.

The role, efficacy and outcome measures for teriparatide use in the management of medication-related osteonecrosis of the jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a complex disease which can be associated with multiple morbidities and is challenging to treat. This review evaluates the literature on the role and efficacy of teriparatide (TPTD) as a treatment for MRONJ. The clinical, radiological, histopathological and serological parameters used to assess treatment response have been described. Electronic databases were searched to retrieve articles (April 2005 and April 2020) based on strict inclusion criteria. Seventeen articles were included in this review. Of the 91 patients treated; only six received TPTD as a standalone treatment. There were significant variations in defining treatment outcomes and measuring treatment response. The longest follow-up period was 26 months, and 12 studies failed to report follow-up. The overall quality of evidence is weak with potential for a high risk of bias, making it difficult to determine the efficacy of TPTD and its long-term effects. However, TPTD may play a role in the treatment of intractable MRONJ in osteoporotic patients or those unfit for surgery. Therefore, randomized clinical trials on larger patient cohorts with long-term follow-up is required to confirm efficacy, safety and inform treatment indications for TPTD in the treatment of MRONJ.

Management of medication-related osteonecrosis of jaw: Comparison between icariin and teriparatide in a rat model

BACKGROUND

The aim of this study is to compare the effects of icariin and teriparatide on the treatment of medication-related osteonecrosis of the jaw (MRONJ) using a rat model.

METHODS

Fifty rats undergoing ovariectomy were randomly assigned to control group (n = 10) and the MRONJ model group (n = 40). Zoledronic acid (0.2 mg/kg) and dexamethasone (2 mg/kg) were injected into rats in the model group for 8 weeks while saline was applied in control group, then all rats underwent tooth extraction and bone defect. Eight weeks later, rats diagnosed with MRONJ (n = 33) were randomly distributed to icariin (n = 11), teriparatide (n = 11), and the untreated (n = 11) group, and rats received daily 150 mg/kg icariin, 20 µg/kg teriparatide, and no intervention, respectively, for 8 weeks. Then, mandibulars were dissected for later examination.

RESULTS

Rats diagnosed with MRONJ (33/40) demonstrated significantly larger area of soft tissue wound and necrotic bone with higher ratio of empty bone lacuna. Area of soft tissue wound and ratio of empty bone lacuna were significantly decreased in the icariin group compared with the untreated group, while teriparatide group revealed significantly higher ratio of receptor activator of NF-kB ligand (RANKL)-positive osteocytes, smaller area of necrotic bone and lower ratio of empty lacuna. The two agents were related to higher expression of BMP-2 in osteocytes but were not statistically significant.

CONCLUSIONS

Icariin benefits MRONJ in terms of the area of soft tissue wound and ratio of empty lacuna. Teriparatide activates expression of RANKL and reduces the area of bone necrosis and ratio of empty lacuna in a MRONJ lesion. The data suggest possible healing improvement in patients with MRONJ and further studies to prove the efficacy of icariin.

Osteoporosis Therapeutics 2020

Numerous safe and efficient drug therapies are currently available to decrease risk of low trauma fractures in patients with osteoporosis including postmenopausal, male, and secondary osteoporosis. In this chapter, we give first an overview of the most important outcomes regarding fracture risk reduction, change in bone mineral density (BMD by DXA) and/or bone markers of the phase III clinical studies of well-established therapies (such as Bisphosphonates, Denosumab or Teriparatide) and also novel therapies (such as Romosozumab or Abaloparatide) and highlight their mechanisms of action at bone tissue/material level. The latter understanding is not only essential for the choice of drug, duration and discontinuation of treatment but also for the interpretation of the clinical outcomes (in particular of eventual changes in BMD) after drug administration. In the second part of this chapter, we focus on the management of different forms of osteoporosis and give a review of the respective current guidelines for treatment. Adverse effects of treatment such as atypical femoral fractures, osteonecrosis of the jaw or influence of fracture healing are considered also in this context.